The present invention relates generally to electronic test equipment. More particularly, the present invention relates to diagnostic and display apparatus for troubleshooting and repair of motor vehicles, to include interface with onboard motor vehicle control computers.
Onboard control computers have become ubiquitous in motor vehicles, as safety, economy, and emissions requirements have continued to escalate, and conventional designs for reciprocating engines, friction braking systems, collision safety apparatus, and traction control devices have proven unequal to the requirements set out in law and the implicit demands of competitors"" achievements. Successive generations of onboard control computers have acquired increasing data sensing and retention capability as the electronic art has advanced. Present external diagnostic and display apparatus, known to those skilled in the art as Scan Tools, are commonly limited to reporting the data acquired by the onboard control computer itself. Increasingly subtle subsystem failures in automobiles overload the ability of maintenance technicians not simply to read the faults detected and stored by the computers themselves, but to combine those readings with peripheral measurements in order to allow a technician to identify faults and decide on corrective actions with both speed and accuracy.
Accordingly, it is desirable to provide in the Scan Tool the ability to acquire and evaluate test data from sources other than the motor vehicle""s onboard computer, and to combine those results with data acquired directly from the onboard computer. The present invention, by enhancing the Scan Tool""s ability to collect data from external test devices via data input ports, and by merging the additional data with data previously available from the onboard computer into a single display with fully coordinated timing, presents to the technician a more complete picture of the status of the motor vehicle under test. By establishing communication with external test devices autonomously through a process that includes attempting and choosing among multiple protocols, the present invention speeds setup and performance of testing in a cost-driven, time-critical environment.
The foregoing limitations of the prior art have been satisfied to a great extent by the present invention, wherein, in a first aspect of the invention, a test apparatus for acquiring and displaying motor vehicle data includes a scan interface subsystem permitting communication between the test apparatus and a motor vehicle onboard diagnostic (OBD) computer, an external device interface subsystem permitting communication between the test apparatus and additional data acquisition devices, and a display in communication with the scan interface and the external device interface component, where the display presents data from the scan interface and from additional data acquisition devices with which the external device interface component may be in communication.
In accordance with another embodiment of the present invention, the Scan Tool is enhanced through the provision of means whereby vehicle status data from multiple sources can be combined and displayed. The present invention provides means whereby fixed data elements from the vehicle""s OBD computer, data from the OBD computer changing at any rate, fixed measurements from other data acquisition devices, and dynamic signals from other data acquisition devices can be gathered, scaled with respect to time delay, rate, and amplitude, then stored or displayed. Whereas previous Scan Tool designs may allow OBD data, external-source data, or a combination of these to be displayed, but each test instrument must be stipulated by the user in order for its data to be captured, the present invention provides means whereby external data devices can be interrogated for their properties and their data captured and incorporated into the display without requiring the user to know their precise interface requirements.
In accordance with another embodiment of the present invention, the Scan Tool provides a method for acquiring and displaying motor vehicle diagnostic data that includes the steps of obtaining data from a computer on a motor vehicle, obtaining data from external test equipment, and displaying data from the computer on the motor vehicle and data from the external test equipment.
There have thus been outlined, rather broadly, the more important features of the invention, in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.